Safe Haskell	Safe-Inferred
Language	Haskell2010

GHC.Tc.Solver.Monad

Description

Monadic definitions for the constraint solver

Synopsis

data TcS a
runTcS :: TcS a -> TcM (a, EvBindMap)
runTcSEarlyAbort :: TcS a -> TcM a
runTcSWithEvBinds :: EvBindsVar -> TcS a -> TcM a
runTcSInerts :: InertSet -> TcS a -> TcM (a, InertSet)
failTcS :: TcRnMessage -> TcS a
warnTcS :: TcRnMessage -> TcS ()
addErrTcS :: TcRnMessage -> TcS ()
wrapTcS :: TcM a -> TcS a
runTcSEqualities :: TcS a -> TcM a
nestTcS :: TcS a -> TcS a
nestImplicTcS :: EvBindsVar -> TcLevel -> TcS a -> TcS a
setEvBindsTcS :: EvBindsVar -> TcS a -> TcS a
emitImplicationTcS :: TcLevel -> SkolemInfoAnon -> [TcTyVar] -> [EvVar] -> Cts -> TcS TcEvBinds
emitTvImplicationTcS :: TcLevel -> SkolemInfoAnon -> [TcTyVar] -> Cts -> TcS ()
selectNextWorkItem :: TcS (Maybe Ct)
getWorkList :: TcS WorkList
updWorkListTcS :: (WorkList -> WorkList) -> TcS ()
pushLevelNoWorkList :: SDoc -> TcS a -> TcS (TcLevel, a)
runTcPluginTcS :: TcPluginM a -> TcS a
addUsedGRE :: Bool -> GlobalRdrElt -> TcS ()
addUsedGREs :: [GlobalRdrElt] -> TcS ()
keepAlive :: Name -> TcS ()
matchGlobalInst :: DynFlags -> Bool -> Class -> [Type] -> TcS ClsInstResult
data ClsInstResult
- = NoInstance
- | OneInst {
  - cir_new_theta :: [TcPredType]
  - cir_mk_ev :: [EvExpr] -> EvTerm
  - cir_what :: InstanceWhat
  }
- | NotSure
data QCInst = QCI {
- qci_ev :: CtEvidence
- qci_tvs :: [TcTyVar]
- qci_pred :: TcPredType
- qci_pend_sc :: Bool
}
panicTcS :: SDoc -> TcS a
traceTcS :: String -> SDoc -> TcS ()
traceFireTcS :: CtEvidence -> SDoc -> TcS ()
bumpStepCountTcS :: TcS ()
csTraceTcS :: SDoc -> TcS ()
wrapErrTcS :: TcM a -> TcS a
wrapWarnTcS :: TcM a -> TcS a
resetUnificationFlag :: TcS Bool
setUnificationFlag :: TcLevel -> TcS ()
data MaybeNew
- = Fresh CtEvidence
- | Cached EvExpr
freshGoals :: [MaybeNew] -> [CtEvidence]
isFresh :: MaybeNew -> Bool
getEvExpr :: MaybeNew -> EvExpr
newTcEvBinds :: TcS EvBindsVar
newNoTcEvBinds :: TcS EvBindsVar
newWantedEq :: CtLoc -> RewriterSet -> Role -> TcType -> TcType -> TcS (CtEvidence, Coercion)
emitNewWantedEq :: CtLoc -> RewriterSet -> Role -> TcType -> TcType -> TcS Coercion
newWanted :: CtLoc -> RewriterSet -> PredType -> TcS MaybeNew
newWantedNC :: CtLoc -> RewriterSet -> PredType -> TcS CtEvidence
newWantedEvVarNC :: CtLoc -> RewriterSet -> TcPredType -> TcS CtEvidence
newBoundEvVarId :: TcPredType -> EvTerm -> TcS EvVar
unifyTyVar :: TcTyVar -> TcType -> TcS ()
reportUnifications :: TcS a -> TcS (Int, a)
touchabilityTest :: CtFlavour -> TcTyVar -> TcType -> TcS TouchabilityTestResult
data TouchabilityTestResult
- = TouchableSameLevel
- | TouchableOuterLevel [TcTyVar] TcLevel
- | Untouchable
setEvBind :: EvBind -> TcS ()
setWantedEq :: HasDebugCallStack => TcEvDest -> Coercion -> TcS ()
setWantedEvTerm :: TcEvDest -> EvTerm -> TcS ()
setEvBindIfWanted :: CtEvidence -> EvTerm -> TcS ()
newEvVar :: TcPredType -> TcS EvVar
newGivenEvVar :: CtLoc -> (TcPredType, EvTerm) -> TcS CtEvidence
newGivenEvVars :: CtLoc -> [(TcPredType, EvTerm)] -> TcS [CtEvidence]
checkReductionDepth :: CtLoc -> TcType -> TcS ()
getSolvedDicts :: TcS (DictMap CtEvidence)
setSolvedDicts :: DictMap CtEvidence -> TcS ()
getInstEnvs :: TcS InstEnvs
getFamInstEnvs :: TcS (FamInstEnv, FamInstEnv)
getTopEnv :: TcS HscEnv
getGblEnv :: TcS TcGblEnv
getLclEnv :: TcS TcLclEnv
setLclEnv :: TcLclEnv -> TcS a -> TcS a
getTcEvBindsVar :: TcS EvBindsVar
getTcLevel :: TcS TcLevel
getTcEvTyCoVars :: EvBindsVar -> TcS TyCoVarSet
getTcEvBindsMap :: EvBindsVar -> TcS EvBindMap
setTcEvBindsMap :: EvBindsVar -> EvBindMap -> TcS ()
tcLookupClass :: Name -> TcS Class
tcLookupId :: Name -> TcS Id
updInertTcS :: (InertSet -> InertSet) -> TcS ()
updInertCans :: (InertCans -> InertCans) -> TcS ()
updInertDicts :: (DictMap Ct -> DictMap Ct) -> TcS ()
updInertIrreds :: (Cts -> Cts) -> TcS ()
getHasGivenEqs :: TcLevel -> TcS (HasGivenEqs, Cts)
setInertCans :: InertCans -> TcS ()
getInertEqs :: TcS InertEqs
getInertCans :: TcS InertCans
getInertGivens :: TcS [Ct]
getInertInsols :: TcS Cts
getInnermostGivenEqLevel :: TcS TcLevel
getTcSInerts :: TcS InertSet
setTcSInerts :: InertSet -> TcS ()
getUnsolvedInerts :: TcS (Bag Implication, Cts)
removeInertCts :: [Ct] -> InertCans -> InertCans
getPendingGivenScs :: TcS [Ct]
addInertCan :: Ct -> TcS ()
insertFunEq :: FunEqMap a -> TyCon -> [Type] -> a -> FunEqMap a
addInertForAll :: QCInst -> TcS ()
emitWorkNC :: [CtEvidence] -> TcS ()
emitWork :: [Ct] -> TcS ()
lookupInertDict :: InertCans -> CtLoc -> Class -> [Type] -> Maybe Ct
kickOutAfterUnification :: TcTyVar -> TcS Int
addInertSafehask :: InertCans -> Ct -> InertCans
insertSafeOverlapFailureTcS :: InstanceWhat -> Ct -> TcS ()
updInertSafehask :: (DictMap Ct -> DictMap Ct) -> TcS ()
getSafeOverlapFailures :: TcS Cts
addSolvedDict :: InstanceWhat -> CtEvidence -> Class -> [Type] -> TcS ()
lookupSolvedDict :: InertSet -> CtLoc -> Class -> [Type] -> Maybe CtEvidence
foldIrreds :: (Ct -> b -> b) -> Cts -> b -> b
lookupFamAppInert :: (CtFlavourRole -> Bool) -> TyCon -> [Type] -> TcS (Maybe (Reduction, CtFlavourRole))
lookupFamAppCache :: TyCon -> [Type] -> TcS (Maybe Reduction)
extendFamAppCache :: TyCon -> [Type] -> Reduction -> TcS ()
pprKicked :: Int -> SDoc
instDFunType :: DFunId -> [DFunInstType] -> TcS ([TcType], TcThetaType)
newFlexiTcSTy :: Kind -> TcS TcType
instFlexi :: [TKVar] -> TcS TCvSubst
instFlexiX :: TCvSubst -> [TKVar] -> TcS TCvSubst
cloneMetaTyVar :: TcTyVar -> TcS TcTyVar
tcInstSkolTyVarsX :: SkolemInfo -> TCvSubst -> [TyVar] -> TcS (TCvSubst, [TcTyVar])
data TcLevel
isFilledMetaTyVar_maybe :: TcTyVar -> TcS (Maybe Type)
isFilledMetaTyVar :: TcTyVar -> TcS Bool
zonkTyCoVarsAndFV :: TcTyCoVarSet -> TcS TcTyCoVarSet
zonkTcType :: TcType -> TcS TcType
zonkTcTypes :: [TcType] -> TcS [TcType]
zonkTcTyVar :: TcTyVar -> TcS TcType
zonkCo :: Coercion -> TcS Coercion
zonkTyCoVarsAndFVList :: [TcTyCoVar] -> TcS [TcTyCoVar]
zonkSimples :: Cts -> TcS Cts
zonkWC :: WantedConstraints -> TcS WantedConstraints
zonkTyCoVarKind :: TcTyCoVar -> TcS TcTyCoVar
newTcRef :: a -> TcS (TcRef a)
readTcRef :: TcRef a -> TcS a
writeTcRef :: TcRef a -> a -> TcS ()
updTcRef :: TcRef a -> (a -> a) -> TcS ()
getDefaultInfo :: TcS ([Type], (Bool, Bool))
getDynFlags :: HasDynFlags m => m DynFlags
getGlobalRdrEnvTcS :: TcS GlobalRdrEnv
matchFam :: TyCon -> [Type] -> TcS (Maybe ReductionN)
matchFamTcM :: TyCon -> [Type] -> TcM (Maybe ReductionN)
checkWellStagedDFun :: CtLoc -> InstanceWhat -> PredType -> TcS ()
pprEq :: TcType -> TcType -> SDoc
breakTyEqCycle_maybe :: CtEvidence -> CheckTyEqResult -> CanEqLHS -> TcType -> TcS (Maybe ReductionN)
rewriterView :: TcType -> Maybe TcType

Documentation

data TcS a Source #

Instances

Instances details

MonadFail TcS Source #
Instance details Defined in GHC.Tc.Solver.Monad Methods fail :: String -> TcS a Source #
MonadIO TcS Source #
Instance details Defined in GHC.Tc.Solver.Monad Methods liftIO :: IO a -> TcS a Source #
Applicative TcS Source #
Instance details Defined in GHC.Tc.Solver.Monad Methods pure :: a -> TcS a Source # (<>) :: TcS (a -> b) -> TcS a -> TcS b Source # liftA2 :: (a -> b -> c) -> TcS a -> TcS b -> TcS c Source # (>) :: TcS a -> TcS b -> TcS b Source # (<*) :: TcS a -> TcS b -> TcS a Source #
Functor TcS Source #
Instance details Defined in GHC.Tc.Solver.Monad Methods fmap :: (a -> b) -> TcS a -> TcS b Source # (<$) :: a -> TcS b -> TcS a Source #
Monad TcS Source #
Instance details Defined in GHC.Tc.Solver.Monad Methods (>>=) :: TcS a -> (a -> TcS b) -> TcS b Source # (>>) :: TcS a -> TcS b -> TcS b Source # return :: a -> TcS a Source #
HasDynFlags TcS Source #
Instance details Defined in GHC.Tc.Solver.Monad Methods getDynFlags :: TcS DynFlags Source #
MonadThings TcS Source #
Instance details Defined in GHC.Tc.Solver.Monad Methods lookupThing :: Name -> TcS TyThing Source # lookupId :: Name -> TcS Id Source # lookupDataCon :: Name -> TcS DataCon Source # lookupTyCon :: Name -> TcS TyCon Source #
MonadUnique TcS Source #
Instance details Defined in GHC.Tc.Solver.Monad Methods getUniqueSupplyM :: TcS UniqSupply Source # getUniqueM :: TcS Unique Source # getUniquesM :: TcS [Unique] Source #
HasModule TcS Source #
Instance details Defined in GHC.Tc.Solver.Monad Methods getModule :: TcS Module Source #

runTcS :: TcS a -> TcM (a, EvBindMap) Source #

runTcSEarlyAbort :: TcS a -> TcM a Source #

This variant of runTcS will immediatley fail upon encountering an insoluble ct. See Note [Speeding up valid hole-fits]. Its one usage site does not need the ev_binds, so we do not return them.

runTcSWithEvBinds :: EvBindsVar -> TcS a -> TcM a Source #

runTcSInerts :: InertSet -> TcS a -> TcM (a, InertSet) Source #

A variant of runTcS that takes and returns an InertSet for later resumption of the TcS session.

failTcS :: TcRnMessage -> TcS a Source #

warnTcS :: TcRnMessage -> TcS () Source #

addErrTcS :: TcRnMessage -> TcS () Source #

wrapTcS :: TcM a -> TcS a Source #

runTcSEqualities :: TcS a -> TcM a Source #

This can deal only with equality constraints.

nestTcS :: TcS a -> TcS a Source #

nestImplicTcS :: EvBindsVar -> TcLevel -> TcS a -> TcS a Source #

setEvBindsTcS :: EvBindsVar -> TcS a -> TcS a Source #

emitImplicationTcS :: TcLevel -> SkolemInfoAnon -> [TcTyVar] -> [EvVar] -> Cts -> TcS TcEvBinds Source #

emitTvImplicationTcS :: TcLevel -> SkolemInfoAnon -> [TcTyVar] -> Cts -> TcS () Source #

selectNextWorkItem :: TcS (Maybe Ct) Source #

getWorkList :: TcS WorkList Source #

updWorkListTcS :: (WorkList -> WorkList) -> TcS () Source #

pushLevelNoWorkList :: SDoc -> TcS a -> TcS (TcLevel, a) Source #

runTcPluginTcS :: TcPluginM a -> TcS a Source #

addUsedGRE :: Bool -> GlobalRdrElt -> TcS () Source #

addUsedGREs :: [GlobalRdrElt] -> TcS () Source #

keepAlive :: Name -> TcS () Source #

matchGlobalInst :: DynFlags -> Bool -> Class -> [Type] -> TcS ClsInstResult Source #

data ClsInstResult Source #

Constructors

NoInstance
OneInst
Fields cir_new_theta :: [TcPredType] cir_mk_ev :: [EvExpr] -> EvTerm cir_what :: InstanceWhat
NotSure

Instances

Instances details

Outputable ClsInstResult Source #
Instance details Defined in GHC.Tc.Instance.Class Methods ppr :: ClsInstResult -> SDoc Source #

data QCInst Source #

Constructors

QCI
Fields qci_ev :: CtEvidence qci_tvs :: [TcTyVar] qci_pred :: TcPredType qci_pend_sc :: Bool

Instances

Instances details

Outputable QCInst Source #
Instance details Defined in GHC.Tc.Types.Constraint Methods ppr :: QCInst -> SDoc Source #

panicTcS :: SDoc -> TcS a Source #

traceTcS :: String -> SDoc -> TcS () Source #

traceFireTcS :: CtEvidence -> SDoc -> TcS () Source #

bumpStepCountTcS :: TcS () Source #

csTraceTcS :: SDoc -> TcS () Source #

wrapErrTcS :: TcM a -> TcS a Source #

wrapWarnTcS :: TcM a -> TcS a Source #

resetUnificationFlag :: TcS Bool Source #

setUnificationFlag :: TcLevel -> TcS () Source #

data MaybeNew Source #

Constructors

Fresh CtEvidence
Cached EvExpr

freshGoals :: [MaybeNew] -> [CtEvidence] Source #

isFresh :: MaybeNew -> Bool Source #

getEvExpr :: MaybeNew -> EvExpr Source #

newTcEvBinds :: TcS EvBindsVar Source #

newNoTcEvBinds :: TcS EvBindsVar Source #

newWantedEq :: CtLoc -> RewriterSet -> Role -> TcType -> TcType -> TcS (CtEvidence, Coercion) Source #

Create a new Wanted constraint holding a coercion hole for an equality between the two types at the given Role.

emitNewWantedEq :: CtLoc -> RewriterSet -> Role -> TcType -> TcType -> TcS Coercion Source #

Emit a new Wanted equality into the work-list

newWanted :: CtLoc -> RewriterSet -> PredType -> TcS MaybeNew Source #

Create a new Wanted constraint, potentially looking up non-equality constraints in the cache instead of creating a new one from scratch.

Deals with both equality and non-equality constraints.

newWantedNC :: CtLoc -> RewriterSet -> PredType -> TcS CtEvidence Source #

Create a new Wanted constraint.

Deals with both equality and non-equality constraints.

Does not attempt to re-use non-equality constraints that already exist in the inert set.

newWantedEvVarNC :: CtLoc -> RewriterSet -> TcPredType -> TcS CtEvidence Source #

Create a new Wanted constraint holding an evidence variable.

Don't use this for equality constraints: use newWantedEq instead.

newBoundEvVarId :: TcPredType -> EvTerm -> TcS EvVar Source #

Make a new Id of the given type, bound (in the monad's EvBinds) to the given term

unifyTyVar :: TcTyVar -> TcType -> TcS () Source #

reportUnifications :: TcS a -> TcS (Int, a) Source #

touchabilityTest :: CtFlavour -> TcTyVar -> TcType -> TcS TouchabilityTestResult Source #

data TouchabilityTestResult Source #

Constructors

TouchableSameLevel
TouchableOuterLevel [TcTyVar] TcLevel
Untouchable

Instances

Instances details

Outputable TouchabilityTestResult Source #
Instance details Defined in GHC.Tc.Solver.Monad Methods ppr :: TouchabilityTestResult -> SDoc Source #

setEvBind :: EvBind -> TcS () Source #

setWantedEq :: HasDebugCallStack => TcEvDest -> Coercion -> TcS () Source #

Equalities only

setWantedEvTerm :: TcEvDest -> EvTerm -> TcS () Source #

Good for both equalities and non-equalities

setEvBindIfWanted :: CtEvidence -> EvTerm -> TcS () Source #

newEvVar :: TcPredType -> TcS EvVar Source #

newGivenEvVar :: CtLoc -> (TcPredType, EvTerm) -> TcS CtEvidence Source #

newGivenEvVars :: CtLoc -> [(TcPredType, EvTerm)] -> TcS [CtEvidence] Source #

checkReductionDepth Source #

Arguments

:: CtLoc
-> TcType	type being reduced
-> TcS ()

Checks if the depth of the given location is too much. Fails if it's too big, with an appropriate error message.

getSolvedDicts :: TcS (DictMap CtEvidence) Source #

setSolvedDicts :: DictMap CtEvidence -> TcS () Source #

getInstEnvs :: TcS InstEnvs Source #

getFamInstEnvs :: TcS (FamInstEnv, FamInstEnv) Source #

getTopEnv :: TcS HscEnv Source #

getGblEnv :: TcS TcGblEnv Source #

getLclEnv :: TcS TcLclEnv Source #

setLclEnv :: TcLclEnv -> TcS a -> TcS a Source #

getTcEvBindsVar :: TcS EvBindsVar Source #

getTcLevel :: TcS TcLevel Source #

getTcEvTyCoVars :: EvBindsVar -> TcS TyCoVarSet Source #

getTcEvBindsMap :: EvBindsVar -> TcS EvBindMap Source #

setTcEvBindsMap :: EvBindsVar -> EvBindMap -> TcS () Source #

tcLookupClass :: Name -> TcS Class Source #

tcLookupId :: Name -> TcS Id Source #

updInertTcS :: (InertSet -> InertSet) -> TcS () Source #

updInertCans :: (InertCans -> InertCans) -> TcS () Source #

updInertDicts :: (DictMap Ct -> DictMap Ct) -> TcS () Source #

updInertIrreds :: (Cts -> Cts) -> TcS () Source #

getHasGivenEqs :: TcLevel -> TcS (HasGivenEqs, Cts) Source #

setInertCans :: InertCans -> TcS () Source #

getInertEqs :: TcS InertEqs Source #

getInertCans :: TcS InertCans Source #

getInertGivens :: TcS [Ct] Source #

getInertInsols :: TcS Cts Source #

getInnermostGivenEqLevel :: TcS TcLevel Source #

getTcSInerts :: TcS InertSet Source #

setTcSInerts :: InertSet -> TcS () Source #

getUnsolvedInerts :: TcS (Bag Implication, Cts) Source #

removeInertCts :: [Ct] -> InertCans -> InertCans Source #

Remove inert constraints from the InertCans, for use when a typechecker plugin wishes to discard a given.

getPendingGivenScs :: TcS [Ct] Source #

addInertCan :: Ct -> TcS () Source #

insertFunEq :: FunEqMap a -> TyCon -> [Type] -> a -> FunEqMap a Source #

addInertForAll :: QCInst -> TcS () Source #

emitWorkNC :: [CtEvidence] -> TcS () Source #

emitWork :: [Ct] -> TcS () Source #

lookupInertDict :: InertCans -> CtLoc -> Class -> [Type] -> Maybe Ct Source #

Look up a dictionary inert.

kickOutAfterUnification :: TcTyVar -> TcS Int Source #

addInertSafehask :: InertCans -> Ct -> InertCans Source #

insertSafeOverlapFailureTcS :: InstanceWhat -> Ct -> TcS () Source #

updInertSafehask :: (DictMap Ct -> DictMap Ct) -> TcS () Source #

getSafeOverlapFailures :: TcS Cts Source #

addSolvedDict :: InstanceWhat -> CtEvidence -> Class -> [Type] -> TcS () Source #

lookupSolvedDict :: InertSet -> CtLoc -> Class -> [Type] -> Maybe CtEvidence Source #

Look up a solved inert.

foldIrreds :: (Ct -> b -> b) -> Cts -> b -> b Source #

lookupFamAppInert :: (CtFlavourRole -> Bool) -> TyCon -> [Type] -> TcS (Maybe (Reduction, CtFlavourRole)) Source #

Looks up a family application in the inerts.

lookupFamAppCache :: TyCon -> [Type] -> TcS (Maybe Reduction) Source #

extendFamAppCache :: TyCon -> [Type] -> Reduction -> TcS () Source #

pprKicked :: Int -> SDoc Source #

instDFunType :: DFunId -> [DFunInstType] -> TcS ([TcType], TcThetaType) Source #

newFlexiTcSTy :: Kind -> TcS TcType Source #

instFlexi :: [TKVar] -> TcS TCvSubst Source #

instFlexiX :: TCvSubst -> [TKVar] -> TcS TCvSubst Source #

cloneMetaTyVar :: TcTyVar -> TcS TcTyVar Source #

tcInstSkolTyVarsX :: SkolemInfo -> TCvSubst -> [TyVar] -> TcS (TCvSubst, [TcTyVar]) Source #

data TcLevel Source #

Instances

Instances details

Outputable TcLevel Source #
Instance details Defined in GHC.Tc.Utils.TcType Methods ppr :: TcLevel -> SDoc Source #
Eq TcLevel Source #
Instance details Defined in GHC.Tc.Utils.TcType Methods (==) :: TcLevel -> TcLevel -> Bool # (/=) :: TcLevel -> TcLevel -> Bool #
Ord TcLevel Source #
Instance details Defined in GHC.Tc.Utils.TcType Methods compare :: TcLevel -> TcLevel -> Ordering # (<) :: TcLevel -> TcLevel -> Bool # (<=) :: TcLevel -> TcLevel -> Bool # (>) :: TcLevel -> TcLevel -> Bool # (>=) :: TcLevel -> TcLevel -> Bool # max :: TcLevel -> TcLevel -> TcLevel # min :: TcLevel -> TcLevel -> TcLevel #

isFilledMetaTyVar_maybe :: TcTyVar -> TcS (Maybe Type) Source #

isFilledMetaTyVar :: TcTyVar -> TcS Bool Source #

zonkTyCoVarsAndFV :: TcTyCoVarSet -> TcS TcTyCoVarSet Source #

zonkTcType :: TcType -> TcS TcType Source #

zonkTcTypes :: [TcType] -> TcS [TcType] Source #

zonkTcTyVar :: TcTyVar -> TcS TcType Source #

zonkCo :: Coercion -> TcS Coercion Source #

zonkTyCoVarsAndFVList :: [TcTyCoVar] -> TcS [TcTyCoVar] Source #

zonkSimples :: Cts -> TcS Cts Source #

zonkWC :: WantedConstraints -> TcS WantedConstraints Source #

zonkTyCoVarKind :: TcTyCoVar -> TcS TcTyCoVar Source #

newTcRef :: a -> TcS (TcRef a) Source #

readTcRef :: TcRef a -> TcS a Source #

writeTcRef :: TcRef a -> a -> TcS () Source #

updTcRef :: TcRef a -> (a -> a) -> TcS () Source #

getDefaultInfo :: TcS ([Type], (Bool, Bool)) Source #

getDynFlags :: HasDynFlags m => m DynFlags Source #

getGlobalRdrEnvTcS :: TcS GlobalRdrEnv Source #

matchFam :: TyCon -> [Type] -> TcS (Maybe ReductionN) Source #

matchFamTcM :: TyCon -> [Type] -> TcM (Maybe ReductionN) Source #

checkWellStagedDFun :: CtLoc -> InstanceWhat -> PredType -> TcS () Source #

pprEq :: TcType -> TcType -> SDoc Source #

breakTyEqCycle_maybe :: CtEvidence -> CheckTyEqResult -> CanEqLHS -> TcType -> TcS (Maybe ReductionN) Source #

Conditionally replace all type family applications in the RHS with fresh variables, emitting givens that relate the type family application to the variable. See Note [Type equality cycles] in GHC.Tc.Solver.Canonical. This only works under conditions as described in the Note; otherwise, returns Nothing.

rewriterView :: TcType -> Maybe TcType Source #